Move annotation key binding not working

Hello Jeremy,

I am not able to move annotations using alt+mousedown0 on a linux machine with a mouse. I have tried using alt+mousedown0 when the annotation is in pinned/unpinned state in the selection tab but no luck. I am able to see a change in the mouse cursor when clicking alt+mousedown0 to indicate the move action but the annotation does not see to move.

I was trying to move the annotation on this website here: [link](https://neuroglancer-demo.appspot.com/#!%7B%22layers%22:%5B%7B%22type%22:%22new%22%2C%22source%22:%22%22%2C%22tab%22:%22source%22%2C%22name%22:%22new%20layer%22%7D%5D%2C%22selectedLayer%22:%7B%22visible%22:true%2C%22layer%22:%22new%20layer%22%7D%2C%22layout%22:%224panel%22%7D)

I am currently working on extending the annotation implementation to support polygons which includes moving/editing polygons on our fork, so if you could point me to where in the code this is implemented I would appreciate it. Also please let me know if I am using the move annotation operation in a wrong way.

Thanks,
Makam